Underreamer



\pril 25, 1933. B, BER-[RAN 1,905,995

UNDERREAMER Filed June 24, 1951 Inventor BEN/AMI 5 BER TRAN AttorneyPatented Apr. 25', 1933 nENiAmm 1'. BERTRAN, or LOS ANGELES, CALIFORNIA,ASSIGNOR OF ONE-HALF TO Josm A. IBERTRAN uunnnnmunn Application filedJune 24,

My invention relates to underreamers particularly adapted forundercutting or underreaming holes in the ground for receiving orconstructing piers or concrete underfootings 1 for buildings and thelike in which the piers or underfootings are provided with enlarged orexpanded bases.

The objects of this invention are: first, to provide a novel, si-mple,economical and efli- 1 cient underreamer of this class; second, toprovide a device of this class whereby a hole may be underreamed to theidentical shape desired, and particularly tosuch shape for constructingan underfooting having the greatest strength in proportion to its mass;third, to provide a device of this class having a very large opening inthe side wall of the dirt receiving bucket, and a cutter or combinedcutter and deflector of substantially the shape of the desired undercutor of the footing, so that the undercut may be quickly made and thematerial quickly directed into the bucket through the opening oropenings, the cutter or combined cutter and deflector being so arrangedas to drawnor direct the cut materials into the bucket and substantiallyclose the openings of the bucket when desiring to remove the outmaterials from the hole;

fourth, to provide a device of this class having no material obstructionwithin the bucket for interfering with thejcut materials beingdischarged thereinto or from interfering with the closing or drawinginwardly of the cutters and deflectors, the cutters and deflectorsconforming substantially to the contour of the bucket when the formerare drawninwar'dly, thus increasing the capacity of the underreamer toits maximum; fifth, to provide novel, simple, economical and efficientmeans of rotating'the bucket for operating the underreamer which meansalso extends the cutters and draws the same inwardly; sixth, to providesimple and positive means for. limiting the outward extension of thecutters or combined cutters and deflectors, said means being readilyadjustable for variously. but positively limiting the outward extensionof the cutters or'combined cutters and deflectors; seventh, to provide a50 novel arrangement of the means for extend- 1931. Serial No. 548,467.

ing and drawing inwardly the cutters whereby maximum force is obtainedfor extending and drawing inwardly the cutters, commensurat withsimplicity of construction; and, eight to provide a device of this classwhich is durable and which will not readily deteriorate or get out oforder.

With these and other objects in View, as will appear hereinafter, I-have devised an underreaming means having certain novel features ofconstruction, combination and arrangement ofparts and portions, as willbe hereinafter described in detail and particularly set forth in theappended claims, reference being had to theaccompanying drawing and tothe characters of reference thereon which form a part of thisapplication in which showing the usual operating member in section; Fig.3 is a sectional elevational view thereof taken through 3-3 of Fig. 1;Fig. 4 is a transverse sectional view thereof taken through of Fig. 3;and, Fig. 5 is a sectional View on a reduced scale showing theapproximate shape of the underreamed hole adapted to be made by myunderreamer.

Like characters of reference refer to simi lar parts and portionsthroughout the views of the drawing.

My underreamer, as illustrated in the drawing, is substantially in theform of a receptacle when in its closed or inoperative position. Thisreceptacle, formed when the underreamer is closed or in its inoperativeposition or condition for underreaming, consists of a cylindrical bucket1, a bottom member 2, deflectors 3, and cutters 4.

The bucket 1 is provided at its diametrically opposite sides withopenings 1a which extend from the lower edge of the member 1, or 95 fromthe bottom member 2 upwardly, preferably the greater portion of thelength of the bucket member. Each opening is formed with a. verticaledge 1b, a short horizontal upper edge 10, and a substantially angular100 edge 1d extending from the edge 10 downwardly in diverging relationwith respect to the edge 16, and preferably slightly curved outward withrespect to the opening. The 5 lower portion of the edge 1d issubstantially vertical, as indicated by 1e, and extends to the loweredge of the bucket member 1.

The deflectors 3 are preferably made from the portions cut out to formthe openings 1a. These deflectors are hinged, by means of strap hinges5, to the bucket member 1, the hinges being secured to the inner sidesof the bucket member and of the deflectors at the vertical edges 1?) ofthe bucket member and corresponding vertical edges 3a of the deflectors.At the free edges of the deflectors are secured the cutters 4. Thecutting means of each deflectorconsists preferably of a cutting member4a and a cutting member 46, the former being substantially helical inshape and conforming substantially to the angular and curved portion ofthe edge 1d, while the latter is positioned vertically and conformssubstantially to the edge 1e of the opening. These cutting members 4aand 4b are secured to the outer side of the deflectors and are providedwith cutting edges 40 which are deflected outwardly slightly, as shownin Fig. 2. When the cutters, or the combined cutters and deflectors, aredrawn inwardly, as shown in Fig. 4, they cover or enclose substantiallythe whole of the openings, and when so drawn inwardly are positionedsubstantially wholly shown in Fig. 4.

Devices of this class are often lowered into and operated in the hole byrods, sometimes known as Kelly bars. In this instance there is securedto the lower end of the rod a bail 7 which is made of heavy plate metalbent into inverted U-shape form. The rod or bar 6 is secured by a bolt 8or other means to a socket 7 at intermediate the ends of the crossportion 7 b of the bail, The legs 7 c of the bail are slightly narrowerthan the cross portion 7b and are shiftably mounted in a verticaldirection in channels at the diametrically opposite sides of the bucketmember. These channels may be formed by securing bars 9 in parallelspaced relation to the inner side of the bucket lnember, as shown bestin Figs. 2 and 3. This bail isconnected by links 10 to eyes 11 securedto the inner sides of the cutters or deflectors adjacent the free edgesand lower end thereof. The upper ends of the links may be pivotallyconnected to the legs or, as shown in the drawing, to eyes 12a at thelower ends of eyebolts 12 which depend from and are swivelly mounted inthe cross portion 7 b of the bail. The eyebolts 12 are preferablypositioned at the opposite sides of the center line of the cross portionof the bail from the sides at which the cutters are positioned in orderto increase the angular within the contour of the bucket member, as-

positions of the links 10 as much as practicable.

From the above, it will be observed that the bail is positivelyconnected to the bucket member through the cutters or deflectors and thelinks so that the underreamer may be readily lowered into and raisedfrom the hole. The rod or Kelly bar 6 is also non-rotatably connectedwith respect to the underreamer so that the bucket member may berotated. rota-ting with it the cutters. As the device is lowered to thebottom of a hole and the bail 7 lowered still farther with respect tothe bucket member, by reason of the weight of the Kelly bar, the bailand the links, the cutters are forced outwardly by the links. When theKelly bar is then rotated, the underreaming operation takes place. Theextent of the underreaming, however, is limited positively by means ofpins 13 which are placed into a pair of diametrically opposed holes lf,these holes being one in each series of vertically spaced apart holes atthe opposite sides of the bucket member and preferably arranged in thechannels in which the legs 70 slide. When the bucket is full, or whenthe cutters are extended to their lateral limits by reason of theengagement of the bail with the stop pins 13, the bar 6 is raised.causing the cutters and deflectors to be drawn inwardly for closing theopenings 1a, permitting the bucket 1 to be removed from the holes. Thepins 13 are successively lowered until the hole is under-reamed to thedesired extent.

The sectional view shown in Fig. 5 indicates substantially that theundercut may be made in any shape desired, the shape depending upon theshape of the cutting edge of the cutters. In this manner an underreamedhole may be obtained of such shape that an underfooting of concrete castin place will be of maximum strength in proportion to the mass ofconcrete used.

When the device is raised above the ground, the material or detritusremoved from the undercut hole may be removed from the device throughthe lower end of the bucket member. For this purpose the bottom member 2is hinged at one side, by means of a hinge 14, to the inner side of thebucket member. The free edge of the bottom member is held in a raisedposition by means of a latch portion 1511 at the lower end of a rod 15.the latch portion engaging a keeper 16 at the inner side of the bottommember. The rod 15 may be provided at its upper end with a handle 15bfor readily controlling the latch.

In the bottom member may be provided cutters 17' which are extendeddownwardly so as to clean out from the bottom of the hole any loosematerials having'dropped therein.

Though I have shown and described a particular construction, combinationand arrangement of parts and portions, I do not wish to be limited tothis particular construction, combination and arrangement, but desire toinclude in the scope of my invention the construction, combination andarrangement substantially as set forth in the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In an underreamer, a bucket having an opening in its side wall, acutter pivotally mounted on a substantially vertical axis on the bucketat said opening, the cutting edge of the cutter being positioned withone end adjacent the pivotal axis of the cutter and extending downwardlyin diverging relation with respect to the axis toward the lower end ofthe bucket, the lower end of thecutter being positioned a considerabledistance outwardly from the pivotal axis of the cutter, and means forforcing the cutter outwardly and drawing the same inwardly, said cutterbeing so shaped as to form an enlargement at the lower end of a holewith the enlargement 25 gradually increasing-toward. the lower end ofthe hole.

2. In an underreamer, a bucket having an opening in its side wall, acutter pivotally mounted on a substantially vertical axis on the bucketat said opening, the cutter having a cutting edge positioned with oneend adj a cent the pivotal axis of the cutter and extending therefromdownwardly in diverging relation with res ct to the axis and inoutwardly curved orm,the lower portion of the cutting edge beingsubstantially vertical and extending with such substantially verticalportion to substantially the lower end of the bucket, and means forforcing the cutter outwardly and drawing the same inwardly about itspivotal axis.

3. In an underreamer, a bucket having an opening in its side wall, acutter pivotally mounted on a substantially vertical axis on the bucketat said opening, the cutting edge of the cutter being positioned withone end adjacent the pivotal axis of the cutter and extending downwardlyin diverging relation with respect to the axis toward the lower end 9 ofthe bucket, the lower end of the cutter being positioneda considerabledistance outwardly from the pivotal axis of the cutter, and means forforcing the cutter outwardly and drawing the same inwardly, said cutterbeing so shaped as to form an enlargement at the lower end of a holewith the enlargement gradually increasing toward the lower end of thehole, there being provided a deflector portion conforming with thecontour of the bucket and extending from the cutting edge to the pivotalaxis, said cutter and deflecting portion, when drawn inwardly,substantially closing said 0 ning and conforming with the contour of t ebucket.

4. In an underreamer, a bucket having an ter outwardly and drawing .thesame inwardly about its pivotal axis, there being provlded a deflectorportion conforming with the contour of the bucket and extending from thecutting edge to the pivotal axis, sa1d cutter and deflecting portion,when drawn inwardly, substantially closing said opening and conformingwith the contour of the bucket.

5. In an underreamer for underreaming holes for receiving concreteunderfootings with bell-shaped bases, a bucket having an opening in theside wall thereof extending from the extreme bottom of said bucketupwardly, the one side being substantially v'ertical and the other sidetapering in curved line from near the lower side upwardly, a cutterpivotally mounted on the wall of the bucket at the vertical side thereofand shaped to conform to said opening and adapted to form a portion ofthe side of the bucket when closed.

6. In an underreamer for underreaming holes for receiving concreteunderfootings with bell-shaped-bases, a bucket having an openin from t eextreme bottom of said bucket upwardly, the one side being substantiallyver tical and the other side tapering in curved line from near'the lowerside upwardly, a cutter pivotally mounted on the wall of the bucket atthe vertical side thereof and shaped to conform to said opening andadapted to form a portion of the side of the bucket when closed, meansfor rotating said bucket, and means for extending and closing saidcutter whereby said cutter will load said bucket when extended androtated and when closed may be raised for carrying the contents of thebucket upwardly and out of the hole being reamed.

7. In an underreamer, a bucket having an unobstructed opening in itsside wall, a cutter pivotally mounted on a substantially ver-' ticalaxis on the bucket at said opening of the same size and shape as 'saidopening, said cutter having a cutting edge positioned with one endadjacent the pivotal axis of the cutter and extending therefromdownwardly in diverging relation with respect to theaxis and inoutwardly curved form to the extreme lower end of the bucket.

8. In an underreamer for underreaming in the side wall thereof extendingholes for receiving concrete underfootings with bell-shaped bases, abucket having an unobstructed opening in its side wall, a cutterpivotally mounted on a substantially ver- 5 tical axis on the bucket atsaid opening of the same size and shape as said opening, said cutterhaving a cutting edge positioned with one end adjacent the pivotal axisof the cutter and extending therefrom downwardly in diverging relationwith respect to the axis and in outwardly curved form to the extremelower end of the bucket.

9. In an underreamer for underreaming holes for receiving concreteunderfootings with bell-shaped bases, a bucket having an unobstructedopening in its side wall, a cutter pivotally mounted on a substantiallyvertical axis on the bucket at said opening of the same size and shapeas said opening, said cutter having a'cutting edge positioned with oneend adjacent the pivotal axis of the cutter and extending therefromdownwardly in diverging relation with respectto the axis and inoutwardly curved form to the extreme lower end of the bucket, saidcutter being so shaped as to form an enlargement at the lower end of thehole with the enlargement gradually increasing toward the lower end ofsaid hole whereby said hole is formed in bell shape at the lower end bythe gradual outward feeding of the cutter while being revolved andwhereby the dirt from the cutter is forced into said bucket and whensaid cutter is moved inwardly holds the same in said bucket,

In testimony whereof, I have hereunto set my hand at Los Angeles,California, this 12th day of June, 1931.

BENJAMIN E. BERTRAN.

